Molecular conformation changes in alkylthiol ligands as a function of size in gold nanoparticles: X-ray absorption studies

The bonding of hexanethiols to gold nanoparticles of 1.5, 2.0 and 3 nm was studied using X-ray Absorption Near Edge Spectroscopy (XANES) and Extended X-ray Absorption Fine Structure (EXAFS). The XANES spectra revealed that a substantial fraction of hexanethiol molecules were weakly bound, in additio...

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Detalles Bibliográficos
Autores principales: Ramallo López, José Martín, Giovanetti, Lisandro José, Requejo, Félix Gregorio, Isaacs, Steven R., Shon, Young-Seok, Salmeron, Miquel
Formato: Articulo Preprint
Lenguaje:Inglés
Publicado: 2006
Materias:
Física
Extended x-ray absorption fine structure
Xanes
Absorption spectroscopy
Chemical bond
Covalent bond
Atomic physics
Materials science
Spectroscopy
Molecule
Absorption (chemistry)
Crystallography
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/126324
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-126324
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Física
Extended x-ray absorption fine structure
Xanes
Absorption spectroscopy
Chemical bond
Covalent bond
Atomic physics
Materials science
Spectroscopy
Molecule
Absorption (chemistry)
Crystallography
spellingShingle Física
Extended x-ray absorption fine structure
Xanes
Absorption spectroscopy
Chemical bond
Covalent bond
Atomic physics
Materials science
Spectroscopy
Molecule
Absorption (chemistry)
Crystallography
Ramallo López, José Martín
Giovanetti, Lisandro José
Requejo, Félix Gregorio
Isaacs, Steven R.
Shon, Young-Seok
Salmeron, Miquel
Molecular conformation changes in alkylthiol ligands as a function of size in gold nanoparticles: X-ray absorption studies
topic_facet Física
Extended x-ray absorption fine structure
Xanes
Absorption spectroscopy
Chemical bond
Covalent bond
Atomic physics
Materials science
Spectroscopy
Molecule
Absorption (chemistry)
Crystallography
description The bonding of hexanethiols to gold nanoparticles of 1.5, 2.0 and 3 nm was studied using X-ray Absorption Near Edge Spectroscopy (XANES) and Extended X-ray Absorption Fine Structure (EXAFS). The XANES spectra revealed that a substantial fraction of hexanethiol molecules were weakly bound, in addition to the molecules forming covalent bonds with Au surface atoms. The weakly bound molecules could be easily removed by washing in dichloromethane. After removal of the weakly bound molecules the S K-edge XANES spectrum reveals peaks due to S-Au and S-C bonds with intensities that change as a function of particle size. We explain this as the result of distortions occurring in the molecules adsorbed on the smaller particles. The distortions arise from the poor packing due to the high curvature of the particles. In addition, EXAFS results show that the smaller particles bind more molecules per Au atom than the larger ones, which is again interpreted as a result of the curved nature of the surface.
format Articulo
Preprint
author Ramallo López, José Martín
Giovanetti, Lisandro José
Requejo, Félix Gregorio
Isaacs, Steven R.
Shon, Young-Seok
Salmeron, Miquel
author_facet Ramallo López, José Martín
Giovanetti, Lisandro José
Requejo, Félix Gregorio
Isaacs, Steven R.
Shon, Young-Seok
Salmeron, Miquel
author_sort Ramallo López, José Martín
title Molecular conformation changes in alkylthiol ligands as a function of size in gold nanoparticles: X-ray absorption studies
title_short Molecular conformation changes in alkylthiol ligands as a function of size in gold nanoparticles: X-ray absorption studies
title_full Molecular conformation changes in alkylthiol ligands as a function of size in gold nanoparticles: X-ray absorption studies
title_fullStr Molecular conformation changes in alkylthiol ligands as a function of size in gold nanoparticles: X-ray absorption studies
title_full_unstemmed Molecular conformation changes in alkylthiol ligands as a function of size in gold nanoparticles: X-ray absorption studies
title_sort molecular conformation changes in alkylthiol ligands as a function of size in gold nanoparticles: x-ray absorption studies
publishDate 2006
url http://sedici.unlp.edu.ar/handle/10915/126324
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AT giovanettilisandrojose molecularconformationchangesinalkylthiolligandsasafunctionofsizeingoldnanoparticlesxrayabsorptionstudies
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AT shonyoungseok molecularconformationchangesinalkylthiolligandsasafunctionofsizeingoldnanoparticlesxrayabsorptionstudies
AT salmeronmiquel molecularconformationchangesinalkylthiolligandsasafunctionofsizeingoldnanoparticlesxrayabsorptionstudies
bdutipo_str Repositorios
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